1. Field of the Invention
This invention relates to vessel moorages and floating breakwaters formed by interconnected marine floats, and more particularly to a system for securing a row of marine floats to each other in relatively rough waters.
2. Description of the Prior Art
Vessel moorages constructed of a large number of interconnected marine floats, generally of concrete, are in common use throughout the United States and other countries. The floats are generally rigid, and the fastening structure for interconnecting individual floats must be sturdy enough to withstand typically rough seas, yet allow pivotal movement between the floats responsive to wave action.
Marine floats are typically interconnected utilizing three distinctly different fastening systems. In one of these systems, the floats are provided with transversely extending tie rods having threaded ends projecting from the sides of the floats. Elongated members or "wales" extending along the sides of the floats are secured to the tie rod ends by nuts threaded onto the tie rod ends. In practice, pairs of wales are generally used in overlapping fashion so that they form a continuous structural member extending along each side of the row of marine floats. This system has many advantageous properties, but it is unacceptable under some circumstances as discussed in greater detail below.
A second commonly used interconnecting hinge system employs various types of fasteners which are attached to the ends or embedded in the float. The embedded or attached fastener for one float is then connected to the embedded fastener of the adjacent float by a flexible or pivoting member which allows the floats to pivot with respect to each other.
The third type of marine float used employs tensioning cables or bars that pass lengthwise through float modules with rubber pads being placed between the float modules as a cushion.
Any of the above described conventional fastening structures can be advantageously used where the moorage is protected by land masses or breakwaters, or where the weather is not particularly severe. However, with the increasing demand for moorage facilities, naturally protected sites are becoming less available. Thus, it is necessary to turn to alternative sites which are often unprotected and thus encounter substantially rougher seas. Furthermore, such alternative sites are often in deeper waters making artificial protective structures such as breakwaters more expensive, sometimes prohibitively so, to construct.
The conventional structures for interconnecting marine floats are often incapable of withstanding the rougher seas encountered at these alternative moorage sites. Interconnecting systems employing wales or post-tension cables or bars do not allow sufficient pivoting action of the floats with respect to each other when fairly large waves are encountered. As a result, the wales sometimes break or the tie rods are pulled out of the floats, or the prestress or post-tension tendons give way. Embedded or attached fasteners, on the other hand, do allow sufficient pivotal movement between floats, but they are often not embedded in the float with sufficient strength and thus sometimes pull loose. Any of these mishaps to marine floats utilizing conventional interconnecting systems are extremely costly because of the damage done to the floats themselves as well as the damage done to vessels secured to the floats.